Grey Discolouration for the Diagnosis of Secondary Caries in Teeth with Class II Amalgam Restorations: An in vitro Study

Abstract

Grey discolouration around occlusal amalgam restorations has been found to be useful for the diagnosis of secondary caries. The aim of the present in vitro study was to establish the validity of grey discolouration of buccal and lingual enamel next to the approximal amalgam of class II restorations for the diagnosis of secondary caries. One hundred buccal and lingual areas next to the approximal parts of a class II filling in molars and premolars were included in the study. Fifty-one areas showed grey discolouration. Validation was performed against radiographs of transverse sections. Both radiolucencies and radiopacities were scored as being caries. The results were: sensitivity 92%, specificity 55%, positive predictive value 22% and negative predictive value 98%. It was concluded that grey discolouration of the approximal walls next to class II amalgam fillings is not useful for the detection of secondary caries, but the absence of grey discolouration gives a good prediction for the absence of secondary caries. This is in contrast to grey discolouration around occlusal amalgam restorations, which was considered to be useful for the diagnosis of secondary caries.

Validity and reliability of methods for the detection of secondary caries around amalgam restorations in primary teeth

“…This fact contributes to emphasize the lower reliability of the tested methods. 24 Hence, tactile examination and radiography would not be the most appropriate methods to detect secondary caries at the dentine threshold, which disagrees with previous findings related to radiographic examination, 7,11,25 but agrees with previous results related to tactile examination. 26 Despite the limitation of the visual index used in detecting early secondary caries due to the difficulty in distinguishing discolorations originated from the restoration or from demineralizations, 6 the visual inspection presented the highest sensitivity Table 1 -Sensitivity, specificity and accuracy of the laser fluorescence, visual inspection, radiography and tactile examination methods for detecting secondary caries lesions in primary teeth at enamel (D2) and dentine (D3) thresholds, and their performance expressed as the area under the ROC curve (Az).…”

Validity of staining and marginal ditching as criteria for diagnosis of secondary caries around occlusal amalgam restorations: an in vitro study

“…Observing the relationship between bluish-grey staining and dentinal demineralization, even when using different indicators, it could be concluded that the color adjacent to a restoration was a poor criterion to predict a subjacent dentinal exposure (4,17). On the other hand, the absence of staining represents a good indicator of the absence of disease (18). For the ditching criterion, the sensitivity (s=0.27) and the PPV (0.46) were low; whereas the NPV was only moderate (0.64).…”

Evaluation of Several Techniques for the Detection of Secondary Caries Adjacent to Amalgam Restorations

“…Color change has been found to be irrelevant to the degree of infection of the tissue beneath the restorations; thus, color change should probably be disregarded in the diagnosis of secondary caries beneath amalgam restorations [Kidd et al, 1995]. On the other hand, while Rudolphy et al [1996] found that gray discoloration was not useful for the detection of secondary caries, they found that the absence of gray discoloration was a good predictor for the absence of secondary caries. In the present study, by changing the VC cutoff to 2, which included gray and blue discoloration as sound, sensitivity became lower and PPV showed a similar pattern to VC cutoff 0 at all CLSM thresholds.…”